Looks like the M15 went from 350 to $630. Huge mark up. If that is the case I will take my chances with Craigslist.

If you buy from Craigslist make sure it is a refurbished concentrator and not one from a home medical situation. They have not been refurbished and made ready for the hobby world. Refurbishing is not something most peeps want to do. But you CAN do it.

Yeah, I know Shawnette, but their prices were much more tempting than others. Too bad Jack had to go that way. I told my wife I should just get a homefill unit. There are some really low hour units here in Phoenix.

I was under the impression that they didn't need to be converted. Are you sure there are modifications made for lampwork other than maybe a different fitting for our hoses?

They don't need to be converted and the fittings aren't even changed (they already work with our hoses). UO makes modifications to the units they sell but I've used medical units since I started lampworking 8 years ago.

www.hobbiesforus.com sells concentrators at great prices. You can get an 8 or 10lpm unit for $600 or less. (Their prices have gone up, but still quite reasonable)

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-Shawnette

the original "everybody get a grip" girl

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Yeah, I know Shawnette, but their prices were much more tempting than others. Too bad Jack had to go that way. I told my wife I should just get a homefill unit. There are some really low hour units here in Phoenix.

When you rob peter to pay paul it is a recipe for disaster. Considering the headaches they were not cheap.

I bought two 5lpm units from a guy on Craigslist. Both had very low hours and hooked up easily with my standard hose connection. I haven't had any issues with either of them. I just changed the filters. They've been great. No need to spend a lot of money.

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Cheryl

"You're only given one little spark of madness. You mustn't lose it." Robin Williams

What in the world are these people talking about when they say that oxygen concentrators need to be converted for lampwork use?

Oxygen concentrators don't need to be converted for lampwork. Some are, though, and I'll explain what, how, and why.

Oxygen concentrators (also called generators) come in various sizes and packages. Some are used in the health care and some are used for industrial applications. When given a similar output (in terms of volume and delivery pressure, and I'll discuss that in more detail below), the biggest difference between a unit sold for health care and a unit sold for an industrial application is the packaging and sound proofing. Medical units can be used for industrial applications, but industrial units cannot be used for medical applications.

Units sold for home or hospital use tend to have easy-to-clean plastic cabinets that have sound reducing insulation built into them, because they are intended to be run next to a person for long stretches of time. Some also have bacteria filters in-line. They also tend to have alarms that sound when flow is interrupted, and most shut themselves off when that happens.

Units sold for industrial applications tend to be housed in metal cabinets (but not always) and some of the very large units do not have a self-contained compressor and require a separate air compressor, dryer, and oil filter (if the air compressor is not oilless). Sound reduction is not an important concern in many of these machines, so they are sometimes louder than their health-care counterparts. They may or may not have an alarm that sounds when flow is blocked, and most will shut themselves off if there is a blockage in flow. Some of the industrial units have better compressors in them than the health care units.

For most lampworking studios, metal cabinets are not a necessity and the associated noise is not always welcomed. The easy to clean, insulated, plastic cabinets are a good choice.

One example of a machine converted to lampworking use is the Regalia. The Regalia is based on the medical IntegraEZ (formerly Integra10). Paulette, from whom I inherited my business, had been selling the Integra10 (a medical machine, contrary to what you might read on a certain glass supplier's site) for lampworking and asked SeQual if they could make a machine that would be easier to use for lampworking. The Regalia was their response. It is built with the tough industrial compressor, has a non-medical software package (does not alarm and shut off when flow is blocked, so you can shut off your oxygen valve at the torch without worry), and is housed in the easy to clean, insulated plastic cabinet (so it is quiet and can run right next to you if you want). SeQual makes other industrial units, but they would be better suited for larger production shops.

Now back to the output. The output of these machines is expressed in terms of flow - the volume produced in a given span of time, usually in liters per minute (LPM) or cubic feet per hour (CFH) - and static pressure (the push behind the flow when you block it, which is different than working or running pressure) measured in pounds per square inch (psi).

When torch manufacturers list the requirements for their torches, they will list out their recommended psi setting. This is not for concentrators. This is what setting you would need to set an oxygen regulator on a tank of oxygen to in order for it to provide the flow (LPM) needed for the torch.

A machine that claims to put out 20 psi may or may not be big enough to feed a torch because that number alone does not tell you the volume of oxygen getting through to the torch. You have to consider the LPM rating, and that is the more important measurement. Some torches do require a little more push behind the flow to get the oxygen through internal restrictions, but even then, they still need adequate flow for the torch to perform well.

Some companies, however, seeing the manufacturers' psi recommendations, but not understanding torches and their needs, have taken machines and changed the output psi to a higher setting. In some cases, the LPM output is also changed. For example, some of the machines out there are made from a used base unit that was designed to put out 5 LPM at ~5 psi. They then modify the machine and boost the psi setting to 15 and change the LPM rating of the machine to 8 LPM. I do not know how extensively the machine is modified beyond that (i.e., are the other components of the machine such as wiring and switches and the compressor and the sieve and all that rated to work together for that kind of output?).

There are machines out there that were originally designed by actual concentrator manufacturers to put out 20 psi (and with 10 LPM, which is adequate flow for most bead torches and the centerfires of larger torches), so altering smaller individual machines to put out 8-10 LPM and 15-20 psi is not necessary. These unaltered high-output machines may be a little more expensive (not much more for the used machines), but you get what you pay for - a machine that was originally designed by engineers and technicians to put out what it puts out.

For large torches that require more flow and more pressure, there is also the option of a pressure boosting system, like the HVLPO2. This system takes regular concentrators, gangs them together, collects their oxygen, and boosts the output pressure (outside of the machines, so it does not alter the machines). This system isn't so converting the individual machines themselves for lampworking, but is taking the practice of ganging machines together and making it work better for certain lampworking set-ups.

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Kimberlyworking glass since 1990 - melting it on a torch since 2002